5.0 Tech Questions and Answers - February 2014

I have three Mustangs with some issues...

Fasten Your Intake

I'm following the Cheaper Sleeper and putting an Explorer GT-40 intake on my '90 LX. Can you tell me where I can get new gaskets and bolts for this intake?

Alex Danford
Scottsdale, AZ

Unless the fasteners from your Fox's OEM intake manifold are severely damaged or in some way unusable, the hardware definitely can be used for securing the new Explorer piece. If sprucing things up is your preference, using ARP's small-block-Ford intake-manifold bolts (for '86-'93 EFI engines) is a great option. Gaskets for the new manifold are available (as '93 Cobra replacement parts) through Ford Racing Performance Parts, Summit Racing Equipment, Latemodel Restoration.com, and AmericanMuscle.com, or your Ford dealer's parts department (as '96-'00 Explorer). We went with ARP's bolts on Project Cheaper Sleeper's engine, and an upper/lower intake gasket that came straight from a dealer parts department.

Old Smokey

I have three Mustangs with some issues, but to keep it simple, right now I'll just stick with the one that baffles me. I have an '01 GT with a stroked Four-Valve and P-1SC ProCharger. It will run just fine for about 20 minutes, then start smoking, then pinging like the old-school, low-octane ping at acceleration, until it eventually stalls and will not start up for about another 10-20 minutes. I'm thinking it's something like oxygen sensors or injectors. It does have a knocking sound that I traced to an injector with my stethoscope (it sounds like an exhaust leak).

I have left fuel in it for long periods of time, but I filled it with new within the last few months. Could it possibly be gunk being sucked up from the bottom? Thanks in advance. I love the magazine. Keep up the good work.

SFC Timothy Fleming
Via email

Your engine's problem could be based on a number of different things. Ring seal (or a lack thereof) in one cylinder leads our list of guesses. However, in all honesty, Sarge, all of the potential causes are a bit too challenging for us to correctly diagnose without actually experiencing the concern in person. We recommend you confer with the shop that installed the supercharger and tunes your 'Stang, or another reputable high-performance facility that can perform compression and other tests that hopefully will get to the bottom of your engine's issue.

Fan Switch

I own a '11 GT and since buying it, I have used it for all sorts of motorsports events. The car has been mostly stock since I got it, with the exception of an axle-back exhaust and cold-air tubing. I'm about to do a bit more modding for drag racing, but nothing too exotic. Do you think I should remap the OEM fan control, so that I can manually switch the fan On (and run it either Low or High) when I need to? This would mostly be for cooling between runs.

Andy Jackson
Trenton, NJ

Dragstrip and dyno tests that we've performed on Coyote-powered 'Stangs, really have proven time-and-time again that heat soak isn't as big a concern with the all-motor set as it typically is with supercharged '11-'14 Ponies. Consistent engine temperature can easily be managed by diligently adhering to the same between-run cooling practice of simply opening the hood and allowing ambient air or an electric fan or air blower (if you have a generator/110-volt power source) to help dissipate underhood air and cool the engine.

Arms' Length

I tried putting a set of 28-inch-tall tires on my '87 Mustang coupe and they rub on the inside of the passenger-side rear quarter-panel. I was told my rearend isn't centered under the car, and that I need adjustable control arms to fix the problem. Is this right? Why would the rear be off-center in the first place?

Name Witheld
Via the Internet

It's possible your Mustang's rearend has shifted, a condition that comes about when the car has been in a rear-area-focused accident, or when the upper torque boxes and control-arm mounts or bushings are compromised/damaged.

We suggest you first confirm the rear is off-center—have a four-wheel-alignment performed on your ride by an alignment or chassis specialist. If your Pony's rear is misaligned, and assuming the car currently has the factory's fixed rear upper and lower control arms, we strongly recommend you replace them with adjustable pieces, which are available through UPR Products.

Centering the rear from side-to-side is done by simply adjusting the upper arms to different lengths (making turns “in” on one arm, and “out” on the other) and moving the housing from side-to-side until it measures as centered.

Prime Time

I have a '12 5.0 Coyote Mustang. I improved the fuel system by adding an electric fuel pump (Aeromotive) and changing to return-style. The pump is properly wired using the correct wire from the power distribution box. The problem is now the fuel pump starts once the ignition is switched on and it never stops, although I don't switch the key over to the run position. I have seen many applications where the pump goes on just for a couple of seconds at the ignition (to prime the fuel system). That's what I'm trying to do, as I think that's how it is with the original pump, right?

Stewart Ross
Via the Internet

Return-style fuel systems had a 2- to 3-second prime cycle to ease starting. This would fill the lines and build pressure for starting. After all, the older return-style fuel systems didn't talk with the computer (they were a complete, standalone system). After 2 to 3 seconds, if the computer didn't see any engine rpm, the pump would shut off.

Your vehicle has a computer-controlled fuel system that talks with your fuel pump through a fuel-pump driver module. However, you've converted to a standalone fuel system and it never was setup to run like that. The factory ECU has no prime circuit, only key-on 12 volts. So, any time the key is switched to On, 12 volts are going straight to the pump. For now, the only way around this is to interrupt the key-on's 12-volt wire with a toggle switch.